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Abstract：
UNASSIGNED: Routine surveillance for antimalarial drug resistance is critical to sustaining the efficacy of artemisinin-based Combination Therapies (ACTs). Plasmodium falciparum kelch-13 (Pfkelch-13) and non-Pfkelch-13 artemisinin (ART) resistance-associated mutations are uncommon in Africa. We investigated polymorphisms in Plasmodium falciparum actin-binding protein (Pfcoronin) associated with in vivo reduced sensitivity to ART in Nigeria.
UNASSIGNED: Fifty-two P. falciparum malaria subjects who met the inclusion criteria were followed up in a 28-day therapeutic efficacy study of artemether-lumefantrine in Lagos, Nigeria. Parasite detection was done by microscopy and molecular diagnostic approaches involving PCR amplification of genes for Pf18S rRNA, varATS, telomere-associated repetitive elements-2 (TARE-2). Pfcoronin and Pfkelch-13 genes were sequenced bi-directionally while clonality of infections was determined using 12 neutral P. falciparum microsatellite loci and msp2 analyses. Antimalarial drugs (sulfadoxine-pyrimethamine, amodiaquine, chloroquine and some quinolones) resistance variants (DHFR_51, DHFR_59, DHFR_108, DHFR_164, MDR1_86, MDR1_184, DHPS_581 and DHPS_613) were genotyped by high-resolution melting (HRM) analysis.
UNASSIGNED: A total of 7 (26.92%) cases were identified either as early treatment failure, late parasitological failure or late clinical failure. Of the four post-treatment infections identified as recrudescence by msp2 genotypes, only one was classified as recrudescence by multilocus microsatellites genotyping. Microsatellite analysis revealed no significant difference in the mean allelic diversity, He, (P = 0.19, Mann-Whitney test). Allele sizes and frequency per locus implicated one isolate. Genetic analysis of this isolate identified two new Pfcoronin SNVs (I68G and L173F) in addition to the P76S earlier reported. Linkage-Disequilibrium as a standardized association index, IAS, between multiple P. falciparum loci revealed significant LD (IAS = 0.2865, P=0.02, Monte-Carlo simulation) around the neutral microsatellite loci. The pfdhfr/pfdhps/pfmdr1 drug resistance-associated haplotypes combinations, (108T/N/51I/164L/59R/581G/86Y/184F), were observed in two samples.
UNASSIGNED: Pfcoronin mutations identified in this study, with potential to impact parasite clearance, may guide investigations on emerging ART tolerance in Nigeria, and West African endemic countries.
UNASSIGNED: Fifty-two P. falciparum malaria subjects who met the inclusion criteria were followed up in a 28-day therapeutic efficacy study of artemether-lumefantrine in Lagos, Nigeria. Parasite detection was done by microscopy and molecular diagnostic approaches involving PCR amplification of genes for Pf18S rRNA, varATS, telomere-associated repetitive elements-2 (TARE-2). Pfcoronin and Pfkelch-13 genes were sequenced bi-directionally while clonality of infections was determined using 12 neutral P. falciparum microsatellite loci and msp2 analyses. Antimalarial drugs (sulfadoxine-pyrimethamine, amodiaquine, chloroquine and some quinolones) resistance variants (DHFR_51, DHFR_59, DHFR_108, DHFR_164, MDR1_86, MDR1_184, DHPS_581 and DHPS_613) were genotyped by high-resolution melting (HRM) analysis.
UNASSIGNED: A total of 7 (26.92%) cases were identified either as early treatment failure, late parasitological failure or late clinical failure. Of the four post-treatment infections identified as recrudescence by msp2 genotypes, only one was classified as recrudescence by multilocus microsatellites genotyping. Microsatellite analysis revealed no significant difference in the mean allelic diversity, He, (P = 0.19, Mann-Whitney test). Allele sizes and frequency per locus implicated one isolate. Genetic analysis of this isolate identified two new Pfcoronin SNVs (I68G and L173F) in addition to the P76S earlier reported. Linkage-Disequilibrium as a standardized association index, IAS, between multiple P. falciparum loci revealed significant LD (IAS = 0.2865, P=0.02, Monte-Carlo simulation) around the neutral microsatellite loci. The pfdhfr/pfdhps/pfmdr1 drug resistance-associated haplotypes combinations, (108T/N/51I/164L/59R/581G/86Y/184F), were observed in two samples.
UNASSIGNED: Pfcoronin mutations identified in this study, with potential to impact parasite clearance, may guide investigations on emerging ART tolerance in Nigeria, and West African endemic countries.
摘要：
■抗疟疾药物耐药性的常规监测对于维持基于青蒿素的联合疗法（ACTs）的疗效至关重要。恶性疟原虫kelch-13（Pfkelch-13）和非Pfkelch-13青蒿素（ART）抗性相关突变在非洲并不常见。我们研究了尼日利亚恶性疟原虫肌动蛋白结合蛋白（Pfcoronin）的多态性，该多态性与体内对ART的敏感性降低有关。
■在拉各斯对52名符合纳入标准的恶性疟原虫疟疾受试者进行了为期28天的蒿甲醚-lumefantrine疗效研究，尼日利亚。通过显微镜和分子诊断方法进行寄生虫检测，包括PCR扩增Pf18SrRNA基因，varATS,端粒相关重复元件-2(TARE-2)。对Pfcoronin和Pfkelch-13基因进行双向测序，同时使用12个中性恶性疟原虫微卫星基因座和msp2分析确定感染的克隆性。抗疟药（磺胺多辛-乙胺嘧啶，阿莫地喹,氯喹和一些喹诺酮类）抗性变体（DHFR_51，DHFR_59，DHFR_108，DHFR_164，MDR1_86，MDR1_184，DHPS_581和DHPS_613）通过高分辨率熔解（HRM）分析进行了基因分型。
■共有7例（26.92％）被确定为早期治疗失败，晚期寄生虫学失败或晚期临床失败。在通过msp2基因型确定为复发的四种治疗后感染中，通过多基因座微卫星基因分型，只有一个被归类为复发。微卫星分析显示平均等位基因多样性没有显着差异，他,(P=0.19,Mann-Whitney检验)。每个基因座的等位基因大小和频率涉及一个分离株。除了先前报道的P76S外，该分离株的遗传分析还鉴定了两种新的PfcoroninSNV（I68G和L173F）。联动-不平衡作为标准化的关联指数，IAS,在多个恶性疟原虫基因座之间，中性微卫星基因座周围显示出显着的LD（IAS=0.2865，P=0.02，蒙特卡罗模拟）。pfdhfr/pfdhps/pfmdr1耐药相关单倍型组合，（108T/N/51I/164L/59R/581G/86Y/184F），在两个样品中观察到。
■本研究中鉴定的Pfcoronin突变，有可能影响寄生虫清除，可能会指导对尼日利亚新兴的ART耐受性的调查，和西非流行国家。
■在拉各斯对52名符合纳入标准的恶性疟原虫疟疾受试者进行了为期28天的蒿甲醚-lumefantrine疗效研究，尼日利亚。通过显微镜和分子诊断方法进行寄生虫检测，包括PCR扩增Pf18SrRNA基因，varATS,端粒相关重复元件-2(TARE-2)。对Pfcoronin和Pfkelch-13基因进行双向测序，同时使用12个中性恶性疟原虫微卫星基因座和msp2分析确定感染的克隆性。抗疟药（磺胺多辛-乙胺嘧啶，阿莫地喹,氯喹和一些喹诺酮类）抗性变体（DHFR_51，DHFR_59，DHFR_108，DHFR_164，MDR1_86，MDR1_184，DHPS_581和DHPS_613）通过高分辨率熔解（HRM）分析进行了基因分型。
■共有7例（26.92％）被确定为早期治疗失败，晚期寄生虫学失败或晚期临床失败。在通过msp2基因型确定为复发的四种治疗后感染中，通过多基因座微卫星基因分型，只有一个被归类为复发。微卫星分析显示平均等位基因多样性没有显着差异，他,(P=0.19,Mann-Whitney检验)。每个基因座的等位基因大小和频率涉及一个分离株。除了先前报道的P76S外，该分离株的遗传分析还鉴定了两种新的PfcoroninSNV（I68G和L173F）。联动-不平衡作为标准化的关联指数，IAS,在多个恶性疟原虫基因座之间，中性微卫星基因座周围显示出显着的LD（IAS=0.2865，P=0.02，蒙特卡罗模拟）。pfdhfr/pfdhps/pfmdr1耐药相关单倍型组合，（108T/N/51I/164L/59R/581G/86Y/184F），在两个样品中观察到。
■本研究中鉴定的Pfcoronin突变，有可能影响寄生虫清除，可能会指导对尼日利亚新兴的ART耐受性的调查，和西非流行国家。
